Generally it is Known that the best clinical results in treatment of injuries of the ankle are obtained by anatomical restoration of the joint. For objective measurements of tibiotalar joint, some investigators ued different criteria and defined the specific reference points under variable angle of internally rotated anteroposterior projection. But, occasionally we didn't acquire the accurate roentgenographic finding that was suggested by investigators. So, we check the variable angle of internal rotation film in addition to angle suggested by investigators and compare the criteria between them. The purpose of this study is to evaluate availability of internally rotated mortise view and its criteria in clinical practice. Following results was acquired. First, there was no significant difference in measuring the medical clear space on depand on variability of rotation angle. Second, the overlapping distance of tibiofibular syndesmosis decreased by increasing internal rotation angle, but was not under 1mm (ie, index of injury). A third, to measure the Weber's 3 criteria, we need to check the variable internal rotation angle, if necessary. Finally, we acquired the normal range of measurement about Tile's 2 criteria by variable internal rotation angle.